docs: def validate_input(self, input_string, validators):
          """
          Validate the given input string against the specified list of validators.
          :param input_string: the input string to verify.
          :param validators: the list of validators.
          :raises InvalidValidator if the list of validators does not provide a valid InputValidator class.
          :return: a boolean representing the validation result. True if the input string is valid; False otherwise.
          """
          validation_result = True
  
          if isinstance(validators, BaseValidator):
              validators = [validators]
          elif validators is None:
              validators = []
  
          if isinstance(validators, list):
              validation_results = []
              for validator in validators:
                  if isinstance(validator, BaseValidator):
                      validation_results.append(validator.validate(input_string=input_string))
                  else:
                      raise InvalidValidator("Validator {} is not a valid validator".format(validator))
  
              validation_result = all(validation_results)
          else:
              raise InvalidValidator("Validator {} is not a valid validator".format(validators))
  
          return validation_result